This study assessed the links between civic participation and adolescent behavior problems (bullying, physical fighting, and alcohol and tobacco use), and whether civic engagement could be a moderator of the negative effects of parent/family detachment. Participants were 7,097 11-, 13-, and 15-year-olds (48.6% girls) in a region of Northern Italy. Twenty percent were involved in some level of civic participation, the majority of which was faith-based. Results showed that adolescents who are involved in civic associations reported slightly less fighting and alcohol and tobacco use, but this relationship varies by sex, age, detachment from parents and family, and the frequency of adolescent participation. For the sample as a whole, a U-shaped relationship was found between civic participation and behavior problems, with the fewest behavior problems associated with moderate frequency of participation (1 to 4 times per week). The expected hypothesis that civic participation moderates the relationship between parent/family detachment and problem behaviors was suggested only for 15-year-old girls but not for younger girls or for boys. Implications for preventive interventions are discussed. (Contains 3 tables and 1 figure.)